Pivots for movably mounting a door to a door frame are well known. Door pivots typically comprise a bottom pivot anchored to the threshold or to the door jamb, which pivotably cooperates with a second portion mounted to the face of the door. A door pivot differs from a hinge primarily in that the axis of rotation of a hinge is coincident to or outside the lateral edge of the door, whereas the axis of rotation of a pivot falls inside the lateral edges of the door.
Door pivots are broadly categorized according to their intended mounting position on the door. All doors require at least two pivots, a top pivot and a bottom pivot. Top pivots do not bear a major portion of the weight of the door but instead are designed primarily to provide an upper pivot point for the door and to withstand lateral forces exerted against the door resulting from the torque applied to open the door. The bottom pivot is the primary load bearing pivot and typically includes a ball bearing located in the door portion of the pivot for enhanced load carrying capability.
Door pivots may be further categorized as either center pivots or offset pivots, depending upon where the axis of rotation of the pivot lies in a vertical plane with respect to the door. With a center pivot, the axis of rotation falls in a vertical plane intermediate the inner and outer stiles of the door. Center pivots are primarily used when it is desired to mount a door which can pivot in both directions. However, in order to position the axis of rotation intermediate the stiles of the door, channels or recesses must be cut into the stiles to mount the pivot. While center pivots are acceptable for mounting interior or vestibule doors, the interruptions in the door required to mount a center pivot make the center pivot undesirable for exterior applications which require weather sealing, since the channels which are cut into the lateral edge of the door to mount the door pivot will permit air and water to pass through.
For such exterior applications which require weather sealing, the offset door pivot is the more desirable alternative. A typical bottom offset door pivot installation is depicted in FIG. 1 of the drawings and includes a generally L-shaped body having a horizontal base portion and an upwardly extending bracket portion. The upwardly extending bracket portion is received within the hollow vertical jamb on the pivot side of the door. The base portion has a recess formed thereon into which a portion of the threshold is received. An upwardly extending spindle is formed on the base portion and is offset from the bracket portion. The spindle cooperates with a corresponding bore on the door portion of the pivot assembly to pivotably mount the door.
One of the difficulties presented by a conventional offset door pivot installation is the requirement that the vertical pivot jamb and the threshold be mortised or otherwise notched to accommodate the bottom pivot. In addition, various punching, drilling, and tapping operations are necessary to mount the door pivot to the door jamb and threshold. These notching, punching, drilling, and tapping operations require time, special machinery, and skilled labor, which increases the cost of installing the door pivot. Thus, there is a need to provide a bottom offset door pivot which minimizes the amount of machining of the door jamb and threshold which is required to install the pivot.
Another problem associated with conventional bottom offset pivots is that a given pivot assembly will be either left-handed or right-handed, depending upon the direction in which the spindle is offset with respect to the bracket member. Such handed pivots cannot be used interchangeably and thus double the inventory of pivots which a building supplier must keep on hand. Further, the possibility of error is introduced, in that a worker may arrive at the work site with, for example, a left-handed pivot to hang a right-handed door, thereby causing aggravation, delay, and increased cost of installation. Finally, there is the possibility that a worker may attempt, either accidentally or unknowingly, to install a wrong-handed pivot for a particular application. Thus, there is a need to provide a non-handed bottom offset door pivot.